University of Tokyo sets two new Net speed records

Demonstrates that IPv6 can match IPv4 performance

Simon Aughton
25 Apr 2007

The University of Tokyo has broken two of the Internet2 Land Speed Records and has now set or broken 10 records for the highest-bandwidth, end-to-end networks.

The first record was set over a next-generation IPv6 network path over 30,000km long and crossing six international networks (over three-quarters of the circumference of the Earth). The Tokyo team successfully transferred data at a rate of 7.67Gbps which is equivalent to 230,100 terabit-metres per second (Tb-m/s) - the rate at which data is transferred multiplied by the distance travelled.

The team used standard TCP network technologies to achieve the new mark.

The following day it used a modified version of TCP to achieve an even greater record. Using the same 30,000km path, the network was able to achieve a throughput of 9.08Gbps, equivalent to 272,400Tb-m/s for both the IPv6 multi and single stream categories.

Internet2, which monitors Land Speed Record attempts, noted that this new IPv6 record surpassed the current IPv4 record of 239,820Tb-m/s, demonstrating that IPv6 networks are able to provide the same, if not better, performance as IPv4.

'These records are final for the 10Gbps network era because they represent more than 98 per cent of the upper limit of network capacity,' said Dr Kei Hiraki, professor at the University of Tokyo and team leader. 'Through collaboration by a number of institutions, we have demonstrated the ability to overcome the distance and achieve this newest mark.'

The principle advantage of the IPv6 protocol over the existing IPv4 system is that it allows for many more individual IP addresses, and its adoption is expected to accelerate as the number of available addresses dwindles.

No-one is quite sure when this will happen, although the US Government has set a 2008 deadline for all civilian and defence vendors to move to IPv6. IPv4 supports a maximum of 4.3 billion addresses. IPv6 will provide 5x1028 addresses for each of the 6.5 billion people in the world's population today.

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